Just in Case: How to be Self-Sufficient When the Unexpected Happens Book

An all-inclusive emergency and preparedness handbook for families just like yours. Packed with practical plans to keep everyone warm, fed and sheltered during a power outage; organize and rotate your food supply; plan and pack an evacuation kit; protect important documents; and even entertain the children for several television-free days.

Oxygen
The presence of oxygen causes food to spoil. Spoilage due to oxygen is most often thought of as a canning problem. Home-canned food that has been canned properly (see Chapter 17) will be as free of oxygen as commercially canned food, and it'll last as long, too.
However, some oxygen exposure can be a problem for some dry foods. Oxygen causes rancidity in fats and allows insects, fungi, and aerobic bacteria to persist. This is a problem in dehydrated foods with a relatively high fat content, such as powdered milk and eggs. It's even a problem for grains with a relatively high fat content (such as brown rice or rolled oats), split peas, and most nuts if they will be stored for more than a year. (It's not a problem for refined products such as white flour, white rice, and degerminated cornmeal, or for whole wheat, corn berries, or dried beans.)
Food purchased for long-term storage will arrive properly sealed so as to exclude as much oxygen from the containers as possible. But food purchased simply in bulk, such as from a natural foods store, will likely come in a plastic bag sealed with a twist tie. Obviously, this will not protect the food from the deleterious effects of oxygen. This is not a problem if you plan to rotate your supplies on a regular basis, but if you do plan to store oxygen-sensitive food such as dried milk for more than a few months, repackaging your supplies with oxygen absorber packets will greatly increase the storage life.